View Full Version : Limit switches?

03-24-2008, 02:30 PM
I recently received my X2 CNC kit. I am planning on fitting limit switches and I need to know if to wire the switches in the "normally closed" position, with the switches opening the circuit when triggered by the machine movement. This seems appropriate but I wanted to check with you guys.



03-30-2008, 12:31 AM
Hi Bill,
I suggest normally closed, I can't remember where I read it, but heres why:
if something happens like a wire gets cut or there is a power failure on the terminal with the switch, the circuit will be open, the controller then stops the machine. If its Normally open, this doesn't happen and the machine will keep going even if it hits the switch.

One further note, i don't know how you plan to wire the switches, I'm just going to wire all 6 (2 per axis) together in series and only use one terminal on the breakout board for my machine. If you do go this route, you need to go normally closed since it will open the circuit when triggered. It won't work if you go normally open since closing one switch will still leave others open, hence the signal doesn't reach the board.
See "wiring sample1" here (http://www.cnc4pc.com/Store/osc/product_info.php?cPath=33&products_id=45)
i will be copying their wiring of the switches
Cheers, Dave.

03-30-2008, 08:22 AM
I agree with Dave. Also the more positive aspect is you dont have anywhere as much wire used in series wiring. (bundle is 1 pair not 6 pair).

Dave did you use the c10 breakout? I am having some difficulty with one.


03-30-2008, 10:57 AM
yes i am using the c10, my machine is not complete yet but I have got the system working with the motors just spinning around not connected to anything.
What sort of issues are you having?

03-30-2008, 02:23 PM
Thanks for the reply but I figured it out...Was using it with a 3 MDFly drivers and one was dead.